In a large pot, melt 3 tablespoons of the butter and cook the artichoke hearts, leek, garlic, onion and shallots until tender but not brown.,Add the potatoes and stock.,Tie up the bay leaf, thyme, parsley and peppercorns in cheesecloth and add to the pot.,Simmer, uncovered, 1 hour.,Remove and discard the herbs.,______,When ready to serve, heat the soup and whisk in the remaining butter and the cream.,Season with salt and serve.